Brake-shoe.



IN0. 695,4l9. Pntlltd Maf. Il, |9D2...

4 A. L; STREETER.-

l BRAKE SHOE. (Anuncian med 1m. 15, 19in.)

Nrrs

raras ATENT rines.

BRAKE-SHOE.

SPECIFICATION forming part of Letters Patent No. 695,419, dated March w11, 1902.

Application nea March 15,v 1901. 'seria No. 51,254.. (Nq man.)

T all whom it may concern:

Be it known that I, ALFRED L. STREETER,

a citizen of theUnitedStates, anda resident` of Chicago, in the county of Cook and State of Illinois, have invented an Improved Brake- Shoe, of which the following is asp'eciiication.

` relates particularly to brake-shoes of the general type comprising an in sert or inserts of relatively hard or soft metal secured in the face or friction-surface thereof.

A primary object of the invention is to eliminate certain objectionable features now common in shoes ofthis type, among which may be mentioned the following: the breaking off of the attaching-,lugwhich allows the entire body portion ot' the shoe to fall and frequently'results in .very serious accidents; loosening andfalling ont of the inserts or of parts thereof orthe breaking-off of parts `of the body portionfof the ',shoe, which occurs quite frequently and materially impairs the efficiency of the shoe, exposing sharp edges, which cut the treads ofthe wheels in breaking in a very objectionable manner.'

A further objectof the invention is to provide a shoe whichwill Abe'eficient for braking purposes and which may be worn veryv thin without resorting tothe luse of separate; plates of steel or other` strengtough metalsecured to the back thereof..

The invention consists of the various other features, combinations of features, anddetails of construction hereinafter .described and claimed.

In the accompanying drawings a brakeshoe of my inventionis fully illustrated.

Figure l is a plan view of the back of a shoe embodying myinvention in vwhat I now considerA its preferredform. Fig. 2.is a similar view of a modified form of brake-shoe of my invention. Figs. 3 and 4 are sectional views on the Vlines 3 3 and 4 4, respectively, of Figs. l and 2; and Figs. 5 and Gare partial sectional views on the lines 5 5 and'G 6, respectively, of Figs. 1 and 2.

Referring now to the drawings, A designates the body portion of the shoe, A an Vinsert secured therein,'and A2 A3 the' attaching and guide lugs, respectively, thereof.

f To effect the object of the invention as it to the insert A.

This invention relatesto brake-shoes, andSi relates to preventing the attaching-lug from breaking off, myinvention consists in securing said attaching-lug A2 directly and rmly What I new consider the preferable form of brake-shoe to eect this object is thaty shown in Figs. 1, 3,and 5 of the drawings, in which said attaching-lug A2 vis formed integral with the insert A", said in- 'sertbcing preferablyl made ofk strong tough Vmetalas wrought-iron, malleable iron, semisteel, or the like-which will insure a connection' of requisite strength between ysaid attaching-lugY andthe body of the shoe.

In lcase the insert Af is made of wrought or malleable lironior other relatively soft metal the body portion A of the shoe will be formed of hard cast-iron', the-soft insert giving the desired coefficient vof friction and the hard body ,portion of the sh'oe` giving life and durability to the shoe. `Incase the insert A' is made of lseini'ste'el -or "other Vrelatively hard metal the'jbody portion A of the shoe will be v formed vof soft cast-iron,the hard insert giving the wear and the soft body portion the desiredy frictional engagement necessary for efficient breaking. My inventionghowever, contemplates forming the attaching-lug A2 separate fromth'efinsert and dovetailingl or otherwise securing saidattaching-lug to said drawings. In this form of theshoe the'portion o. ofthe'insert'to which the attaching-,lug A2 is directly attached is preferably raised -somewhat 'above the" backofthe shoe--say one- 'eighth of an inch-thus insuring a `firm connection between said attaching-lug and insert i at all stages of wear of theshoe. In this form of the shoe also the attaching-lug will be formed integral 'with the body portion A of the shoe, and toprovide a strong connection between the body portion ofsaid shoe and said attaching-lugthe insert A is cut away, as shown at a', Fig. 2, thus increasing the thickness of the body portion of the shoe beneath the attaching-lng.

In this form of the shoe the insert A may be madeof any dl sired hard or soft metal, the body portionof the shoe being relatively soft or hard, respectively, as compared therewith.

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To effect the object of my invention as it relates to providing a shoe of requisite strength as the shoe approaches the limit of its wear, i

a shoe of my invention comprises an insert or inserts which are of substantially the same length as the brake-shoe and which extend substantially entirely through the shoe from front to back thereof, as clearly shown in the d rawings,Figs. 1 to G,both inclusive,and which are made of strong tough metal, as wroughtiron, malleable iron, steel, or the like. Vith this construction it is obvious that as the brake-shoe approaches the limit of its wear the insert will provide requisite strength to prevent the shoe from breaking.

In order to bind the inserts and the body portions of the shoes securely together to pre- .vent the inserts from becoming loose and dropping or portions of the shoe from breaking off and falling, said inserts and the body portions of the shoes are firmly dovetailed to each other, as clearly shown at a2, Figs. l and 2 of the drawings. This can be effected in a simple and economical manner in the process of making the shoes, as follows: The inserts are first formed with suitable dovetail openings in their sides or lateral faces, which preferably extend from front to back thereof. The body portions of the shoes are then cast around said inserts, the molten metal entering and filling the dovetail openings in the sides of the inserts, thus forming the dovetails a2. This process could of course be reversed, the body portions being formed first and the inserts afterward cast into them.

As shown, the dovetail openings a2 are substantially circular in cross-section, the centers thereof being located inwardly from the sides of the inserts. Said openings will thus be wider back from the sides of said inserts than they are in the sides thereof in the desired manner. Any other desired form of dovetail openings may, however, be used.

The shape of the inserts is immaterial. As best adapted to effect the various objects of my present invention, however, and to combine in a single shoe the various advantages arising therefrom, I consider the form of the insert shown in the drawings to be preferable. Said insert consists of a single integral piece of suitable metal of substantially the same general outline as the body portion of the shoe, but enough smaller to give a desired body of metal outside thereof.

When inserts of size and shape substantially as shown in the drawings are used, the proper relative proportions of hard and soft metal in the faces or friction-surfaces of the shoes may be obtained by making the dovetails a2 of suitable size. In practice, however, and in order to secure a more uniform distribution of the hard and soft metal I prefer to make the dovetails a2 relatively small and to provide holes or openings a3 in the inserts, which preferably extend entirely through them and are filled with the same metal as that of which the body portions of the shoes are formed. A further advantage of this construction when the attaching-lug is made separate from the insert and is dovetailed thereto, as shown in Figs. 2, 4, and G of the drawings, is that by disposing one of the openings a3 beneath the attaching-lug an additional connection is provided between said attaching-lug and the insert. The relative areas of the body portions of the shoes may be further increased, if desired, by forming the guidelugs A3 integral with the body portions of the shoes, suitable holes or openings being formed in or adjacent to the ends of said inserts and which preferably extend from front to back thereof to form a connection of desired size and strength between said guide-lugs and the body portions of the shoes, substantially in the manner shown at 61,4 in the drawings. My invention, however, contemplates forming said guide-lugs A3 integral with the inserts, if desired. With this construction the ends of the body portions of the shoes will preferably be dovetailed to the inserts in the same manner as the sides thereof.

In order to render the shoes strongerand to prevent their breaking, particularly in handling, I prefer to form the shoes with thin layers-say one-eighth (-t') of an inch thickof the metal, of which the body portions of the shoes are formed, covering the backs and the initial friction-surfaces thereof, as shown in Figs. l, 3, and 5 of the drawings.

I claiml. Abrake-shoe comprising an insert which is of substantially the same length as the shoe and extends practically through the shoe from front to back thereof and an attaching-lug secured directly to said insert, substantially as described.

42. A brake-shoe comprising an insert of strong, tough metal which is of substantially the same length as the shoe and extends practically entirely through the shoe from front to back thereof and an attaching-lug formed integral with said insert, substantially as described.

3. A brake-shoe comprisinga body portion and a rigid insert inclosed within the body portion of the shoe and which extends to within a short distance of the back and of the initial face or friction-surface of the shoe, sub

stantially as described.

In testimony that I claim the foregoing as my invention I have hereunto set my hand this 12th day of March, 1901.

ALFRED L. STREE'IER.

vv ltnesses:

ARTHUR F. Evans, C. J. BRoUen'roN.

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